Homostylium albescens var. rugosum Z. X. Fu 2025, comb. nov.

1.10.Homostylium albescens var. rugosum(Y. Ling) Z. X. Fu comb. nov. ≡ Aster albescens var. rugosus Y. Ling, Fl. Reipubl. Popularis Sin. 74: 358, 184. 1985. Type: China, Yunnan, Qinghua university 5895 (holotype, PE 02050377!) (Suppl. material 1: fig. S 20). = Sinosidus albescens var. rugosus (Y. Ling) G. L. Nesom, Phytoneuron 2020-64: 13. 2020. Type: China, Sichuan, Kangding, 1893, Soulie 900 (paratypes, PE 02050375!, PE 02050376!) (Suppl. material 1: figs S 21, S 22). Type. China • Yunnan, Qinghua university 5895 (holotype, PE 02050377!) (Suppl. material 1: fig. S 20). Diagnosis. Leaves oblong-lanceolate, adaxially hispidulous, reticulate veins prominent, areoles of reticulate veins with foamy process. Leaf shape is similar to that of the previous varieties, but with more prominently raised reticulate venation, making the interveinal areas bullate, adaxially sparsely hispidulous. Distribution. China, NW Yunnan (Dali) and W Sichuan (Huili). Habitat. Subalpine. Etymology. The varietal name “ rugosum ” is derived from the Latin “ ruga ”, meaning “ wrinkle ” or “ fold ”, combined with the neuter suffix “ - osum ”, meaning “ full of ” or “ abundant in ”. The name likely refers to the uneven leaf surface, indicating the presence of a foamy process on the adaxial surface. Specimens examined. China • Sichuan: Huili, T. T. Yu 1605 (PE); Kangding, Soulie 900 (PE 02050375, PE 02050376); • Yunnan: Precise locality unknown, Qinghua university 5895 (PE 02050377). Notes. The polymorphism of H. albescens is evident. In addition to the varieties listed herein, there is also a variety of Homostylium albescens var. niveum distributed in Sikkim. According to Grierson (1964), its abaxial leaf surface is covered with cottony tomentum. The plants observed in western China with a cottony tomentose abaxial leaf surface should likely be merged into either H. albescens var. limprichtii or H. albescens var. harrowianum.